- last updated 04/12/11 14:07:03
Avo CT-160 - last updated 26/08/06 21:34:52
Shown on the right is one of my Avo CT-160 portable valve testers. The one in the pic is c.1962, which gives some idea of the durability and quality of these testers.
In addition to the go/no-go facilities offered by testers, this one allows measurement of anode current to be made with surprising accuracy. It allows allows mutual conductance (gm) to be measured - this is invaluable for applications requiring matched valves.
Different heater voltages are catered for, as are different anode and screen voltage, all selected by clearly marked rotary switches.
Gas testing is available, which will give an idea of the amount of residual gas in a tube, and will allow leaky seals to be detected before a "flash" occurs.
Also checks rectifiers and signal diodes to see what kind of shape they are in.
For instructions on how to use it, click here. David Crittle has the calibration instructions on his site - you can read them by clicking here.
|Tests||Filament, Insulation, cathode/heater leakage resistance to 25M ohms, gas, current draw, mutual conductance.|
|Bases||British 4/5/7/9 pin (B4/B5/B7/B7A/B9), P type base (8SC), International
Octal, Mazda Octal, UX4, UX5, UX6, UX7, American SM7, American loctal (B8B or B8G),
B9D, B8D, Hivac 4 pin (SM4), Hivac 5 pin (SM5), B7G (miniature), B9A (noval), B3G, 5AA and
7AA for Acorn valves, F8, B8A, B5A.
Two uncommitted clips which can be connected to top cap or side cap connections.
|Mains||Selectable 105-120 in 5V steps, 175-250 in 5V steps @ 50-500Hz. AC.|
|Heater||0.625, 1.25, 1.4, 2.0, 2.5, 3.0, 4.0, 4.5, 5.0, 5.7, 6.3, 7.5, 10, 11, 12.6, 13, 15, 16, 18, 20, 23, 25, 28, 30, 35, 40, 45, 48, 55, 70, 80, 117|
|Anode||20, 40, 60, 75, 90, 100, 150, 200, 250, 300, 400|
|Screen||20, 40, 60, 75, 90, 100, 125, 150, 200, 250, 300|
|Grid||Continuously variable from 0 to -40V.|
|Other||Measures anode current up to 100mA, gm from 0-20mA/Vm, diode/rectifier efficiency, short circuit protected.|
|Oh yes, and it's portable!|
|Show on the left is an early advertisement for these testers, kindly
donated by Martin Ackroyd.
You can click on the picture to see the full size version.